The Gentoo Security Team discovered that several ebuilds, such as
sys-apps/portage, net-mail/fetchmail or app-editors/leo execute Python
code using "python -c", which includes the current working directory in
Python's module search path. For several ebuild functions, Portage did
not change the working directory from emerge's working directory.

Impact

A local attacker could place a specially crafted Python module in a
directory (such as /tmp) and entice the root user to run commands such
as "emerge sys-apps/portage" from that directory, resulting in the
execution of arbitrary Python code with root privileges.